SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97bd5231c4a5926edd8e144c82198792c3f68c892af4d0ba7a2b78e8605818cc' 
  AND token = 'ROPALS9W0IWsK8TjMaJ5KJh0K2wY2VGUyusRwk9GAkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}